A service provider is an entity (e.g., a business or an organization) that sells bandwidth provided by a network (e.g., the Internet, a data network, a telecommunication network, etc.) associated with the service provider. Service providers may include telecommunications companies, data carriers, wireless communications providers, Internet service providers, cable television operators offering high-speed Internet access, etc. The rapid growth in the use of content, such as, for example, video, audio, images, and software downloads, is creating much higher bandwidth demands on service providers, with sharp bandwidth peaks that may be due to suddenly popular content or the occurrence of events.
In order to address such higher bandwidth demands, service providers deploy proxy cache devices, such as, cache servers, in their networks. The cache servers can cache popular content, which enables the service providers to optimize network utilization and to save on the backhaul bandwidth costs. Cache servers are typically implemented at Layer 7, which is the application layer of the Open Systems Interconnection (OSI) model. The cache servers may be associated with network devices (e.g., routers) that interconnect client devices requesting content and origin devices storing the requested content.
If a request is for content that is stored in the cache server, then the cache server provides the content to the client device. If the requested content is not stored in the cache server, then the cache server connects to the origin device and requests the content from the origin device. The cache server provides the content returned by the origin device to the client device, and may cache the content for future use.
However, if the origin device is incorrectly configured to point to the cache server, a request for content stored in the origin device may create a loop between the cache server and the origin device. Thus, one or more transactions (e.g., the request) may loop through the cache server and the origin device. The loop may cause a buildup of outstanding requests at the cache server, which may cause a service disruption due to resource exhaustion in the cache server.